History is shaped by the use of power, and different people leading the same Union army, with therefore approximately the same power, applied it so differently that the army seemed to change from a pack of noble fools at Fredricksburg to panicked cowards melting away at Chancellorsville, then to the grimly determined, stubborn soldiers who held the ridges at Gettysburg, and then finally to the disciplined, professional army that ground Lee to dust in Grant's long campaign.
It wasn't the soldiers who changed. It was the leader. A great military leader imposes his will on his enemy, and makes his own army a willing extension of himself.
- by Orson Scott Card
Of General Interest